Finn Posted December 20, 2010 Share Posted December 20, 2010 Hi guys, I am after some shear pins for the drop down series pto. I might would like to buy a larger quantity. Can anyone help? Cheers, Finn Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 20, 2010 Share Posted December 20, 2010 I believe most people use a bolt of suitable material. Quote Link to comment Share on other sites More sharing options...
western Posted December 20, 2010 Share Posted December 20, 2010 try a agricultural supplier, shear pins are used in balers & similar machinery Quote Link to comment Share on other sites More sharing options...
Finn Posted December 20, 2010 Author Share Posted December 20, 2010 Ok, has anyone got an idea about the load they will have to be. I believe 2280 kg, is that correct? Thanks, Finn Quote Link to comment Share on other sites More sharing options...
western Posted December 20, 2010 Share Posted December 20, 2010 in my copy of LR's Winching in safety book, it says rated line pull 2268kg or 5000lbs Quote Link to comment Share on other sites More sharing options...
zoltan Posted December 20, 2010 Share Posted December 20, 2010 Just out of interest*, what diameter are the PTO ones? *<anorak on> Quote Link to comment Share on other sites More sharing options...
Finn Posted December 20, 2010 Author Share Posted December 20, 2010 I think 6,5 mm Cheers, Finn Quote Link to comment Share on other sites More sharing options...
Finn Posted December 20, 2010 Author Share Posted December 20, 2010 Does anyone know what kind of bold I could use instead of a shear pin? Cheers, Finn Quote Link to comment Share on other sites More sharing options...
zoltan Posted December 20, 2010 Share Posted December 20, 2010 The pin on my Gaz winch is 5mm. That is a pretty helty winch, 5 tons I seem to recall? I had no pin so I have used a 6mm 12.9 cap screw and turned the shank down (I needed an M6 thread under the head) I was trying to pull a Zil out with it a few weeks back so the 5mm pin is definitely up to the job. It is however on the PTO shaft side connecting to the worm so much lighter loaded Quote Link to comment Share on other sites More sharing options...
Steve Hiatt Posted December 21, 2010 Share Posted December 21, 2010 Does anyone know what kind of bold I could use instead of a shear pin? Cheers, Finn I use a few on agricultural stuff and they are usually 8.8. We now use normal bolts as they are much cheaper and appear no different (I know there used to be a difference at college!) If you think they break too easy, up the strength or drill out to the next size up. Quote Link to comment Share on other sites More sharing options...
Finn Posted December 21, 2010 Author Share Posted December 21, 2010 If I take normal bolts, do I have to make a 'break-line'? Or can I just take the bolt and hope it breaks 'somewhere'? Cheers, Finn Quote Link to comment Share on other sites More sharing options...
steve b Posted December 21, 2010 Share Posted December 21, 2010 Aren't the std ones made of brass? if so this has a much lower shear strength than mild steel/8.8 bolt. I'd start with a machined groove , say down to 4mm and do a bit of winching with a known load - a swb with the wheels locked up on dry tarmac. If it will drag it without shearing it should be about right. .....having said that I know several people that run with HT bolts or even bolt the shear drive flanges together.. cheers Steveb Quote Link to comment Share on other sites More sharing options...
Finn Posted December 21, 2010 Author Share Posted December 21, 2010 Yes, the original one is out of brass.. I broke it yesterday by hand when I added the extra drive flange for the back.. Quote Link to comment Share on other sites More sharing options...
Finn Posted December 21, 2010 Author Share Posted December 21, 2010 Well, I found some at blanchards. I have a side question. How does this work on a defender PTO, does these also have shear pins? Have never seen one.. Cheers, Finn Quote Link to comment Share on other sites More sharing options...
western Posted December 21, 2010 Share Posted December 21, 2010 Well, I found some at blanchards. I have a side question. How does this work on a defender PTO, does these also have shear pins? Have never seen one.. Cheers, Finn in the book I referred to above, it says 'Overlaod Protection Device' can be preset, what the OPD is I don't know, possibly a clutch with a adjustable slip. Quote Link to comment Share on other sites More sharing options...
steve b Posted December 21, 2010 Share Posted December 21, 2010 The LT230 drop box pto has an adjustable sprung ball clutch - the two drive flanges have holes drilled that the ball seats into with most of the ball protruding, the driven plate then has large belleville washers between it and a large ring nut - tighten the nut = more pressure on the balls in the seats . At overload the plate moves against the spring force and the balls roll in a machined track in both drive flanges. The ring nut is locked by a grub screw iirc ...these can also be tightened to the point they are fully locked.. cheers Steveb Quote Link to comment Share on other sites More sharing options...
Finn Posted December 22, 2010 Author Share Posted December 22, 2010 Ok, I added some drawings out of a parts book I found on my harddrive. Lets say you have pulled something way too heavy. Do you need to replace anything, or is it just a case of putting everything (the balls) back at its place and tighten the nut? Cheers, Finn Quote Link to comment Share on other sites More sharing options...
elbekko Posted December 22, 2010 Share Posted December 22, 2010 Looks to me like the ball will just compress the spring, unless of course the bolt is fully tightened, and that's when something will snap. Quote Link to comment Share on other sites More sharing options...
steve b Posted December 22, 2010 Share Posted December 22, 2010 Yep , it just reseats the balls and away you go , much more useable than the series set up cheers Steveb Quote Link to comment Share on other sites More sharing options...
Finn Posted December 22, 2010 Author Share Posted December 22, 2010 Are you referring to ball partnr. 35? Cheers, Finn Quote Link to comment Share on other sites More sharing options...
elbekko Posted December 22, 2010 Share Posted December 22, 2010 I was referring to #22, but that might actually be the wrong bit. The operation seems similar though. Quote Link to comment Share on other sites More sharing options...
steve b Posted December 22, 2010 Share Posted December 22, 2010 Yeah pt no 35 , one for each seat = 3 per unit Are you thinking of converting the series pto to this style? ..would be a good mod to do cheers Steveb Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted December 22, 2010 Share Posted December 22, 2010 ...these can also be tightened to the point they are fully locked.. cheers Steveb Or, as I did weld the sod up to stop the clickyclickityclickrrRRrrrrrRRrrrr noises Nige Quote Link to comment Share on other sites More sharing options...
Finn Posted December 22, 2010 Author Share Posted December 22, 2010 Yeah I am thinking of doing that.. So these balls cannot fall out when overloaded? They stay in the pto..? Cheers, Finn Quote Link to comment Share on other sites More sharing options...
steve b Posted December 22, 2010 Share Posted December 22, 2010 They do indeed, ...and Tavarich HfH , I did think about adding welding up as I've seen that too, usually when the drop box needs a new chain.. cheers Steveb Quote Link to comment Share on other sites More sharing options...
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